Circuit-controlling apparatus.



N. WILKINSON.

CIRCUIT CONTROLLING APPARATUS.

APPLIOATIOIK FILED JUNE 27, 1910.

Patented Feb. 6, 1912.

| I El J I kl] MMAAAAMM IVVVVVVYYVV UNITED STATES PATENT OFFICE.

NATHAN WILKINSON, or MILWAUKEE, WISCONSIN, 'AssIoNoR T0 ALLIs-cmLmEBs COMPANY, A CORPORATION or NEW JERSEY.

CIRCUIT-CONTROLLING APPARATUS.

Patented Feb. 6, 1912.

Application filed June 27, 1910. Serial No. 569,017.

To all whom it may concern:

Be it known that I, NATHAN WILKINSON,

a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented certain new and useful Improvements in Circuit- Controlling Apparatus, of which the following is a full, clear, and exact specification.

My invention relates to protective devices for electric apparatus, and particularly to no-voltage and time limit overload protective devices in combination with potential starters for polyphase induction motors.

In the operation of e1ectric,translating devices of various sorts, it is often desirable that the circuit be interrupted in case either the voltage of the supply circuit fails or there is an overload on the translating device. Often, however, it is undesirable that the breaking of the circuit occur immediately upon an overload, as in some classes of apparatus, such, for instance, as electric motors, it is often necessary that a temporary overload be permitted. In order to take care of this, time limit devices of various sorts have been proposed; and have been combined with the overload and novoltage circuit-controlling means.

My present invention relates to arrangements of this sort. There is a time limit device, which is operative only during the continuance of predetermined abnormal conditions, such'as an overload on a translating device, and this time limit device, upon being operated for a certain time, causes the deenergization ofa holding magnet, which is preferably so-connected that it is also deenergized upon failure of voltage -on the supply circuit; the deenergization of this holding magnet causes the opening of the circuit.

The time limit device, in the preferred form of my invention, is' an electrically heated thermostat. The timeinterval provided by the time'limit device may be either dependent on or independent of the current taken by the translatin device during the continuance of the over oad. This form of protectivemeans is especially applicable in the control of electric motors, and consequently I have shown it, and in some of my claims will claim it, in combination with an electric motor and its control apparatus T he various novel features of my invention will be apparent fromthe description particularly such controller; and Fig.3 shows diagram-' matically a slightly modified system of conmotions.

The details of the starting controller proper will not be fully described here, since in the main they form no part of the present invention and are unnecessary toan understanding thereof.

The three-phase induction motor M is supplied with current from the'three phase mains f, g, and it, through a controller C. When the controller is in off position, the motor is entirely disconnected. When the cont-roller is in starting'position the autotransformer windings 10 and 10 are each connected'between two of the mains, the main h being connected to one terminal of each winding. 011s of the terminals of the motor M is connected to those two terminals of the windings 10 and 10 which are connected in common to the main h, and the other two motor terminals are connected to stitute in effect a single V-connected autotransformer, the main in and the middle terminal of the motor being connected to the middle of the V. When the controller is in running position the auto-transformer windings 10 and 10 are entirely disconnected, and the motor terminals are connected directly to the three mains respectively. In the controller shown there is hut- 7 one starting position between oil and running positions, but it is obvious that any desired number of such starting positions may be employed.

The normal 0 eration of "the controller C 1s always in t e same d1rect1on, av movement through 180 constituting a complete operation. The controller druin is moved by the operating handle 11 through suitable connecting mechanism. The opposite halves of the controller drum are identical in structure, and each half co6perates in turn with each of two sets of contact fingers during successive operations of the controh handle 11 is therefore provided with a spring-pressed pawl 12 which cooperates with a fixed notched plate 13 provided with notches 14, 14*, 14, and 14 The notches 14* and 14 prevent backward movement from the oif positions, in one of which positions the handle ll-is shown in Fig. 2, and

the notches 14 and 14 prevent backward movement from the running positions. The plate 13 may be also provided with sharp inclines 15 and 15? to mark the starting positions of the controller by requiring increased pressure to move the controller forward beyond such positions. The notches 14 and 14 allow the controller to move forward freely from the running positions; but in order toguard against accidental forward movement of the controller from the off positions, the notches 14 and 14 are so designed that in order to move the controller forward from such positions the pawl 12 must be lifted out of the notch 14 or 14 which it occupies. This'is accomplished by means of a push but-ton 16 which cotiperates with a pin 16 on the rod of the pawl 12. -The push button 16 can lift the pawl 12 to clear the low or forward sides of the notches 14 and 14, but not high enough to clear the high or rearward sides of any of the notches of the plate 13.

Fixed on the shaft 17 of the operating handle 11 is a cam wheel 18 whereon are two stops 19 and 19. A bell-crank lever 20, pivoted at 21, is biased in a clockwise direction by means of a spring 22, and carries a roller 23 which rides on the periphery of the cam wheel 18; whereby the spring 22 biases the controller backward to ofi position when it is in starting position or at any point in its movement between ofi position and a point just short of running position, and biases it forward to off position when it has been moved forward beyond. such point. Thus the controller is biased forward to off position when it is in running position. The cam 18 and bell-crank lever 20 are shown in full lines as they .would be with the controller in off position and in dotted lines as they would be with the controller in running position. When the controller is moved to running position, one or the other of the stops 19 and 19 strikes a stop 24 mounted on an arm 25 pivoted at 26. A component of any force transmitted to the arm 25 from a clockwise pressure on the cam 18, such as is exerted when the controller is in running position by the spring 22 or by forward manual pres sure on the handle 11, tends'to move said arm in j ,connected, either directly or through a ,po-

tential transformer, across two of the leads of the motor M, preferably on the motor side of the controller C. The short end of the lever 28 is normally nearly in line with the link 27, so that the no-voltage magnet- 30, acting on the weighted end of the lever 28, need not be unduly large in order to prevent the spring 22 from moving the controller from running position to oft position in spite of the engagement of the stop 19 or 19* with the stop 24. Such forward movement of the controller, however, takes place immediately upon the deenergization of the no-voltage magnet 30, or upon The the application of -suflicient forward pres- 1n the several moto leads. The coils 32 'may be connected 'directly either in the mains, in parallel, if desired, with shunts which may or may not be adjustable, or in the secondary circuits of .current transformers; and, if desired,-may be adjustable, as by rheostats'such as '32 (Fig. 3), to respond to diiferent' strengths of current in the motor leads. There may be an overload relay for each main as, illustrated in Fig. 1-, or for some lesser number of mains. It is often sufficient to provide but one overload relay, as shown in Fig. 3, the load on the several phases of an induction motor generally being fairly well balanced. If there is more than one switch 31, the several switches are connected in series. In shunt to the switch or switches 31 is a thermal time element device, such as a thermostat 33. This. thermostat usually consists of two strips of metal with dissimilar temperature coefficients of expansion, so that upon to excessive currents I aim to cover in the aforesaid the shunt around the. thermostat 33 and causing current to flow through the thermostat 33 and its heating coil 35, part of the current also flowing, perhaps, through the rheostat 36.- The thermostat immediately begins to heat and tends to bend away from the contact 34, finall provided theoverload continues andthe switch or switches) 31 remains open sufficiently long, breaking the circuit of the no-voltage magnet, 30, thus denergizing. said magnet and allowing 'thespring 22 to move the controller forward from the running to the off position. If the .overload ceases before the thermostat leaves the contact 34, the heating circuit of the thermostat is deenergized and the thermostat cools again without having caused an interruption of the motor circuit. The heating circuit of the thermostat 33, may carry only the current for the no-voltage magnet 30, as shown in Fig. 1, in which case the time interval is independent of the extent of the overload on the motor M; or it may'carry a current proportional to the main motor current, (and also, if desired, the no-voltage magnet current), as shown in Fig. 3, in which case the time interval between the beginning of the overload and the movement ofthe controller from the running to off position varies inversely as the overload on the motor.

Various changes may be made in the particular arrangement here shown and described, and all such which do not depart from thespirit and scope of my invention following claims.

What I claim as new is:

1. In a controlle'n'a controller drum normally movable always in the same direction and having oil, starting, and running positions, said drum being biased backward to ofif position when it is in astarting position and forward to ofi position when it is in running position, a magnet on the terminals of which is impressed a voltage varying substantially in proportion to the voltage of the supply circuit, means operative while such magnet is energized for preventing the bias from being effective when the controller is in running position, a thermostatic switch in the circuit of said magnet, said thermostatic switch being normally closed and arranged to open upon being heated, a switch controlling the heating of said thermostat, and means for operating said last mentioned-switch upon an overload.

2. In a controller, a controller drum.normally movable always in the same direction and hav ng ofi, starting, and running positions, said drum being biased backward to of? position when it is instart-ing position and forward to ofiposition when it is in running position, a magnet on the terminals of which is impressed a voltage varying-s stantially in proportion to the voltage of the,

I venting such bias from being "supply circuit, means operative while such.

magnet is energized for preventing the aforesaid bias from being effective when the controller is in running position, and means for deener izing said magnet upon the continuance 0% an overload for a predetermined time.

3. In a controller, a controller drum normally movable always inthe same direction and having ofi, starting, and running positions, said drum being biased backward to off position when it is in starting position and forward to off position when it is in running position, a magnet on the terminals of which is impressed a voltage varying substantially in proportion to the voltage of the supply circuit, means operative While such magnet is energized for preventing the aforesaid bias from being effective when the controller is in running position, a thermal time limit device arranged when'heated to cause the denergization of said magnet, and means for heating said thermal device during the continuance of an overload 4. In a controller, a movable member which when in-running position is biased to off position, a no-voltagemagnet for normally preventing said bias from being effective, a thermostat having a heating circuit and controlling said no-voltage magnet, and means for energizing the heating circuit of said thermostat upon an overload.

5. In a controller; a movable member which when in running position is biased to off posltlon, a no-voltage magnet for preefiective, a

thermal device controlling said no-voltage magnet, and means for heating said thermal device only during the continuance of an overload.

6. In a controller, a 'movable member which when in running position is biased to 05 position, a magnet which when energized prevents movement of said member in response to such bias, a thermal device which when heated causes the denergization of said magnet, and means for causing heating of said thermal device during the continuance of predetermined abnormal conditions.

7. In a controller, a movable member which when in running position is biased to ofi position, a magnet which when energized prevents such bias from being efi'ective, a

thermal device having a heating circuit and arranged in series with said magnet to break the magnet circuit upon being heated, and means for energizing the heating circuit of said thermal device upon an overload.

8. In a controller, a movable member which when in running position is biased to oil position, a magnet which when energized prevents such bias from being effective. a. thermal device having a heating circuit and arranged in series with said magnet to break the magnet circuit upon being heated, a

switch in shunt to said heating circuit, and means for opening said switch upon an overloa 9. In a controller, a movable member which iwhenin running position is biased to oiI position, a magnet which when energized prevents such bias from being effective, a time element device connected in the circuit of said magnet and arranged to open said circuit after having been operated for a predetermined time, and means for causing the operation of said time element device during the continuance of predetermined conditions.

10. In a controller, amovable member which when in running position is biased to off position, a magnet which when energized prevents movement of said movable member in response to such bias, a time element device which when operated for a sufiicient time causes the deenergization of such magnet, and means for causlng the operation of said time element device durlng the continuance of an overload.

11. In a controller, a movable member which when in running position is biased to off position, a no-voltage magnet which when energized prevents such bias "from being effective, a time element device which when operated causes the deenergization of said no-voltage magnet, and means responsive to an overload for causing the operation of said time element device during the continuance of such overload.

12. In a circuit-controlling device, fixed and movable members, saidmovable memher having open and closed positions and when in a closed position being biased to an open position, a no-voltage magnet for preventing such bias from being efiective, a thermal device controlling said no-voltage magnet and arranged when heated to cause the denergization thereof, and means for causing the heating of said thermal device only during the continuance of an overload.

13. In a circuit-controlling device, fixed and movable members, means tending to move the movable member from a closed to an open position,va no-voltage magnet for preventing such movement, a thermostat and a switch in shunt to each other and inseries with said no-voltage magnet, and

when in a closed position being biased to open position, a magnet for preventing movement of the controlling device in response to such bias, a thermostatic device in the circuit of said magnet and arranged when heated by the passage of current to break such circuit, a short-circuit around said thermostat, and means for opening said short-circuit upon an overload.

17. In combination, a circuit-controlling device which when in a closed position is biased to an open position, a magnet which when energized prevents it from moving in response to such bias, a thermostat arranged when heated by the passage of current to cause the deenergization of said magnet, a switch .normally short-circuiting said thermostat, and means responsive to predetermined conditions for opening said switch.

18. In combination, a circuit-controlling device which when in a closed position is biased to an open position, a no-voltage magnet which when energized prevents it from moving in response to such bias, a thermostat arranged when heated by the passage of current to cause the deenergization of said magnet, a switch normally short-circuiting said thermostat, and means respon-' sive to an overload for opening said switch.

19. In combination, a circuit-controlling device which when in a closed position is biased to an openposition, a magnet which when energized prevents it from moving in response to such bias, a time element device which when operated for a sufficient time causes the denergization of such-magnet, and means for causing the operation of said time element device during the continuance of predetermined conditions.

20. In combination, a circuit-controlling lll device which when in a closed position is biased to an open position, a no-voltage magnet which when energized prevents 1t from moving in response to such bias, a time element device arranged when operated for a certain time to cause the deenergization of such no-voltage magnet, and means responsive to an overload for causing the operation of said time element device during the continuance of such overload.

21. In combination, a circuit-controlling device which when in a closed position is biased to an open position, a magnet which when energized prevents such bias from being eifective, a time element device which. when operated for acertain time interrupts the circuit of said magnet, and means for causing the operation of said time element device only during the continuance of predetermined abnormal conditions- 22. In combination, a circuit-controlling device which when in a closed" position is biased to an open position, a no-voltage magnet which when energized prevents such bias from being effective, a time element device which when operated for a certain time breaks the circuit of said no-voltage magnet, and overload-responsive means for causing the operation of said time element device only during the continuance of an overload.

23'. In a controller,,a movable member having oil, starting, and running positions, a magnet controlling the movement of such member from running position to OH position, a thermal device controlling said 'magnet, and means for causing the heating of said. thermal device only'during the cont-inuance of predetermined abnormal conditions.

24. In a controller, a movable member having ofl", starting, and running positions,

. means including a thermal device for controlling the movement of said member from running position to off position, and means for causing the heating of said thermal device only-during the continuance of predetermined abnormal conditions.

25. In a controller, a movable member, a magnet controlling the movement of said member from running position to ofl position, a thermal device having a heating circuit and controlling said magnet, a switch in shunt to said heating circuit, and means independent of the current through said switch for opening said switch upon the occurrence of predetermined abnormal conditions.

26. In a controller, a movable member, means including a thermal device for controlling the movement of said member from running position to off position, said thermal device having a heating circuit, a switch in shunt to said heating circuit, and means independent of the current through said switch for opening said switch-upon an overload.

27. In acontroller, a movable member, a magnet which controls the movement of said member from running position to oil osition, a thermostat controlling the circuit of said magnet, a switch in shunt to said thermostat, and means independent of the current through said switch for opening said switch upon an overload.

28. In a controller, a movable member, means including a thermostat for controlling the movement of said member from running position to off position, a switch in shunt to said thermostat, and means independent of the current through said switch 'for opening said switch upon the occurrence of predetermined abnormal conditions.

29. In a circuit-controlling device, fixed and movable members, a magnet controlling the opening movementv of said movable 4 member, a thermostat and a switch in shunt to each other and controlling said magnet, and means independent of the current through said switch for opening said swltch upon the occurrence of predetermined a b-.

normal conditions.

30. In a circuit-controlling device, fixed and movable members, means including a thermal device for controlling the opening movement of said movable member, said thermal device having a heating circuit, a switch in shunt to said heating circuit, and means independent of the current through said switch for opening said switch upon an overload.

31. In combination, a circuit, a thermostat, a switch which is in shunt to said thermostat and is opened upon the occurrence of predetermined conditions in said circuit independently of the current through --the switch, and means controlled by said thermostat for opening said circuit.

32. In combination, a controlled circuit, a thermal device having a heating circuit, a switch in shunt to said heating circuit, means independent of the current through said switch for opening said switch upon the occurrence of predetermined conditions in said circuit, and means controlled by said thermal device for opening said circuit.

Milwaukee, Wis., June 21, 1910. In testimony whereof I affix my signature, in the presence of two witnesses.

NATHAN WILKINSON.

, Witnesses:

Gno. B. SoHLEY, CHAs. L. BYRON. 

